JP3457957B2 - Method for alkylating aromatic compounds in hydrogen fluoride - Google Patents

Abstract

A continuous process is disclosed for the acylation or alkylation of aromatic compounds in hydrogen fluoride. The aromatic compound is sufficiently insoluble in hydrogen fluoride that a two phase reaction medium forms. However, surprisingly, the product acylated or alkylated aromatic compound is soluble in hydrogen fluoride. The present invention particularly relates to use of a continuous, multi-stage process for carrying out the acylation or alkylation reaction. In the multi-stage process, the continuous phase can be either the hydrogen-fluoride rich phase or the aromatic compound-rich phase. The movement of the continuous phase relative to the non-continuous (dispersed) phase can be countercurrent or concurrent. The multi-stage process can be operated in a manner such that the aromatic compound feed to the reaction is entirely consumed or such that unreacted aromatic compound is recycled. <IMAGE>

Description

Detailed Description of the Invention

This application is directed to US Pat. No. 4,990,681 1990 10
US Application No. filed on May 5th 07 / 593,143 C
Corresponds to IP application.

The present invention relates to the acylation or alkylation of aromatic compounds in hydrogen fluoride, where the acylated or alkylated product is soluble in hydrogen fluoride,
It relates to those in which the aromatic compound is not sufficiently soluble in hydrogen fluoride, which forms the medium of the two-phase reaction. In particular, the invention relates to a continuous, multi-step process for carrying out the acylation or alkylation of aromatic compounds in hydrogen fluoride.

US Pat. No. No. 3,385,886, ibuprofen (ibupup) in which the first step is the reaction of phenylalkane and acetyl chloride to form alkylphenylacetophenone in the presence of aluminum chloride.
The formation of derivatives of phenylalkanes such as rofen) is disclosed.

Japanese Patent Laid-Open No. 60-188,343 discloses
Disclosed is a method for producing isobutylbenzene of p-isobutylacetophenone using acetyl fluoride synthesized by the reaction of acetic anhydride and hydrogen fluoride, and a combination of hydrogen fluoride and boron trifluoride as a catalyst.

Journal of the Chem
ical Society, 4943-4945 [19
56], Baddely et al., On page 4945, disclose a process for the preparation of 4'-isobutylacetophenone by Friedel-Crafts acylation with acetyl chloride of isobutylbenzene using aluminum chloride as a catalyst.

US Pat. No. No. 4,981,995, 1
Published on January 1, 991, Elango et al. Used isobutylbenzene (IBB) to convert acetyl fluoride (Ac
F) or an acetylating agent such as acetic anhydride (Ac ₂ O), the preparation of 4′-isobutylacetophenone (IBAP) by Friedel-Crafts acetylation using a catalyst such as hydrogen fluoride is disclosed. 4'-isobutylacetophenone is disclosed as an intermediate product for the production of ibuprofen.

US Patent N, issued February 5, 1991
o. 4,990,681 is the production of IBAP and IBA
Disclosed is the operation of an extraction reactor for the removal of HF from the P product by reacting HF with acetic anhydride in an HF removal column, both of which can be used in combination with the process of the invention. US Patent No. All disclosures of 4,990,681 are incorporated by reference.

Acylation or alkylation of aromatic compounds in hydrogen fluoride is known. Typical aromatic compound reactants have limited solubility in hydrogen fluoride,
Therefore, contact between the aromatic compound and the acylating or alkylating agent is also limited, and the reaction rate is reduced. Traditionally, acylation or alkylation of aromatics in hydrogen fluoride has been performed in batch mode, typically in a continuous stirred batch reactor, due to the low reaction rate.

Examples of aromatic compounds which form a clearly separated phase with hydrogen fluoride are the Dolkady Akadem.
ii Nauk USSR, 95 (2), 297-29.
9 (1954) and Zhurnal Fizeche
skoi Khimii, 31, 1377-1386
(1957). Aromatics that are slightly soluble in hydrogen fluoride (approximately 1% or less) include naphthalene, phanthrene, diphenylmethane, triphenylmethane, chloronezene, tetralin, 2-methylnaphthalene, and diphenyl. Many aromatics, especially those with -H or -alkyl substitution, have low solubility in hydrogen fluoride. Therefore, those skilled in the art can understand the wide applicability and usefulness of the reaction method capable of continuous acylation or alkylation of aromatic compounds in hydrogen fluoride.

According to the present invention, there is provided a method of continuous acylation or alkylation of an aromatic compound in hydrogen fluoride, the aromatic compound having a well limited solubility in hydrogen fluoride. Having, a two-phase reaction system is formed. The continuous process is carried out countercurrently or cocurrently in a multistage reactor. The continuous phase during the reaction contact can be either an aromatic compound containing phase or a hydrogen fluoride containing phase. The invention is particularly advantageous in that hydrogen fluoride fulfills at least three functions: a catalyst, a reaction medium (solvent) and (surprisingly) an extractant for the acylation or alkylation products of aromatic compounds. Is. Furthermore, depending on the acylating agent used, hydrogen fluoride also acts as an acylating agent.

The process of the present invention is a continuous process for the acylation or alkylation of aromatic compounds in hydrogen fluoride comprising: a) hydrogen fluoride and at least one acylating or alkylating agent. To an extraction reactor to form a first hydrogen fluoride-rich phase, b) supplying a material containing an aromatic compound to the extraction reactor to form a second aromatic compound-rich phase And c) contacting the first hydrogen fluoride-rich phase with some of the second aromatic compound-rich phase in the extraction reactor,
Reacting the acylating agent or alkylating agent with the aromatic compound to form an acylating product or alkylating product of the aromatic compound, and extracting into a hydrogen fluoride phase. To do.

To illustrate the process according to the invention, an acylating agent which may be acetyl fluoride (AcF), acetic anhydride, acetic acid or mixtures thereof in a hydrogen fluoride catalyst / solvent (acetylation 4′-isobutylacetophenone (IBA) by Friedel-Crafts acetylation of isobutylbenzene (IBB) with
Generation of P) will be described. The acylation or alkylation of other aromatic compounds, which also has a limited solubility in hydrogen fluoride, will then be described.

According to the invention, IBAP is a continuous process in which IBB reacts with an acetylating agent in the presence of liquid HF as catalyst / solvent in a multi-stage reactor such as a single extraction reactor. Manufactured in.

According to one embodiment of the present invention, the hydrogen fluoride (HF) -containing phase in the reaction system is a continuous phase,
Light IBB, which is substantially insoluble in HF, is an IBB-rich phase,
For example, forming a droplet, which is HF containing an acetylating agent.
Penetrate upward through the enriched phase. IB formed
AP was selectively dissolved and extracted into the HF-rich phase, unreacted IBB bulk was removed and freshly supplied IB
It is recycled with B to the extraction reactor. Recycled I
BB can be further produced before being returned to the extraction reactor. Product stream is IBAP, HF, small amount of IB
B, often withdrawn from vessels containing varying amounts of acetic acid and acetyl fluoride, the amount of these components depends on other conditions, the nature of the acetylating agent initially added. As used herein, the term "feed poi"
nt) ”or“ point of wi ”
"thdrawal)" means one or more points in the extraction reactor at which the indicated streams are fed or withdrawn.

Since IBB dissolves in the HF-rich phase in small amounts, the portion of the phase below the feed point of fresh IBB and recycled IBB often contains small amounts of IBB. Since this amount is economically important, it increases the residence time between the feed point of the IBB and the exit point of the product stream, ie in the finishing zone, and a significant portion of the IBB dissolved in the HF-rich phase is The chance of reacting with the acetylating agent present in the phase increases, increasing the amount of IBAP produced. Such finishing zones may, for example, have a substantial amount of IB
IBB dissolved in HF-rich phase when B-rich phase is not present
It can be at the bottom, below the IBB feed point, of the extraction reactor containing only. In another, or further preferred example, the product stream is moved and kept in a separate vessel as the finishing zone, i.e. in the finishing reactor for a period of time dissolved in the homogeneous system IBB.
Is kept ready for further acetylation.

According to another aspect of the present invention, the operation of the extraction reactor described above comprises acetic anhydride and HF in IBAP / HF,
Reacting in the product of an extraction reactor in the presence of an acetic acid / HF complex to react acetyl fluoride (AcF) with at least a portion of the stream recycled to the extraction reactor, along with HF withdrawn as an overhead stream. Combined with the operation of the resulting HF removal column. The bottom stream from the HF removal column contains IBAP and some of it acetic acid (HOAc) produced in the previous reaction.

According to yet another aspect of the present invention, the bottom stream from the HF removal column comprises a bulk IB of acetic acid.
From the AP, it is led to a light ends column which is separated along with at least part of the acetic acid recycled to the extraction reactor.

According to another aspect of the invention, the extraction reactor is operated such that the discontinuous phase is present only part of the length of the reactor and the need for recirculation of the discontinuous phase material can be assessed. To be done. Further, the feed ratio of the reactants containing the discontinuous phase is limited to the reactant / melt ratio in the continuous phase prior to removing the continuous phase from the extraction reactor. This embodiment is preferably used when the acylated or alkylated aromatic compound is unstable in the HF-containing phase of the reaction medium and the contact time is limited.

The first exemplification of the invention is 4'-isobutylacetophenone (IBAP) by Friedel-Crafts acylation of isobutylbenzene (IBB),
It is shown by the following formula.

[0020]

[Chemical 1]

In the formula, "X" is a residue obtained by removing the acetyl group of the acetylating agent.

The acetylating agent used is, for example, acetyl fluoride (X = F), acetic anhydride (X = -OCO).
CH _3), and acetic acid (X = -OH). Mixtures of acetylating agents can also be used and can be mixed in situ when acetylating agents such as acetic anhydride are used. Acetic anhydride reacts with IBB to produce IBAP and acetic acid, which is also an acetylating agent. Furthermore, acetic anhydride is HF
It also reacts with other acetylating agents to form acetyl fluoride and acetic acid. If acetic acid is used as all or part of the acetylating agent, some of its anhydrides can also be used and are preferably added to the reaction system for reaction with water. According to another method, when acetyl fluoride is present, it also reacts with water to produce HF and acetic acid. The reaction product thus comprises IBAP and HF and / or free acetic acid, in each case a considerable amount of HF is present. This is because a large excess is used as solvent / extractant / catalyst, for example IBB / I
About 7 to 80 moles are used per mole of BAP. Recirculation ratio, ie the weight of IBB recycled from or near the top of the IBB feed point and preferably H
The ratio to the total weight of material entering or exiting at or below the feed point of F and the reactor acetylating agent at steady state, for example, in the range of about 2 to about 0.03, preferably about It is in the range of 0.5 to 0.1. The use of packing in the extraction reactor increases the contact between the HF-enriched phase and the IBB-enriched phase, which of the IBB-enriched phase is preferably discontinuous in the HF-enriched phase, which is preferably continuous. Preferred, as it aids plug flow and is preferred. The reaction is conducted, for example, at about 45 ° C. to 80 ° C., for example at a boiling pressure of about 35 psig to about 150 psig, for example at a residence time of about 0.3 to 4 hours.

The product of the extraction reactor is sent to the finishing zone of the extraction reactor or to another finishing reactor to maximize the conversion of IBB to IBAP in homogeneous phase. Such finishing zones or reactors are operated at conditions equivalent to the temperature and pressure in the extraction reactor,
The residence time is, for example, about 0.1 to about 4 hours, preferably about 0.5 to 2 hours. Finishing zone or reactor is plug flow conditions (by packing reactor) or laminar flow
Used in conditions.

The product stream is withdrawn from the extraction reactor or the finishing reactor using free or substantially uncomplexed HF and acetic anhydride or acetic acid as all or part of the IBAP and acetylating agent. In some cases, it contains HF complexed with acetyl fluoride. The product stream contains HF, water, and / or acetic acid, which are formed as byproducts of the acetylation reaction. Some of the acetic acid present is HF
And tends to form composites. Furthermore, the product stream is
Depending on the extent of reaction or the initial stoichiometry, unreacted isobutylbenzene (IBB), acetyl fluoride (AcF), acetic acid (HOAc), and acetic anhydride (A
c ₂ O).

To separate the complexed and uncomplexed HF from the IBAP and acetic acid contained in the product stream of the extraction reactor, the stream can be sent to an HF removal column, the operation of which is US Patent No. 4,99
0,681, the description of which is referenced above. In that operation, acetic acid (AC ₂ O) is added to the column below the feed point of the stream entering the column (including aromatic ketone and HF) and reacts with the complexed HF,
Acetyl fluoride (AcF) and acetic acid (HOAc) are produced as shown in the following formula.

Ac ₂ O + HF ---> AcF + HOAc Acetylfluoride is relatively volatile and is withdrawn from the top of the column along with uncomplexed HF and separated from the incoming stream at or near its feed point.
Some IBB, if present, can be collected with overhead for recycling to the reactor. A stream containing the less volatile IBAP and acetic acid is withdrawn from the bottom of the column. The reaction and stripping operations carried out in the HF removal column are, for example, from about 30 ° C to about 15 ° C.
It is performed at a temperature of 5 ° C. and at a pressure of, for example, about 0 psig to about 25 psig.

Some of the desired IBAP product, partially recovered system acetyl, is sent to the light column end for further purification of the bottoms stream from the HF removal column. IBAP at the light column end
And heavier components from the bottom of the column are acetic acid taken from the top of the column, the acetic acid being partly recycled to the extraction reactor where it was acting as part of the acetylating agent. Can be separated from. The light column end has a bottom temperature, for example, about 160 ° C. to about 200
It is operated at a temperature of about 30 mmHg to about 110 mmHg. If desired, the bottom stream from the light column end can be sent to a heavy end column where IBAP removes most of the heavy impurities that were mixed in the bottom stream.
Can be further purified.

Referring to FIG. 1, a stream containing a mixture of liquid HF and an acetylating agent enters the system through line 1 and is continuously sent by a pump 2 to an extraction reactor 3 having a plurality of openings. It exits as a plurality of streams from the liquid distributor 4 below the IBB enriched phase collected at the top of the extraction reactor 3. The mixture containing HF and acetylating agent moves down the dense, preferably extraction reactor 3 through the continuous HF-rich phase. The light IBB enrichment phase is
Extracted from the top of the extraction reactor 3 and connected the line 5 to the IB
B It flows as a recirculation flow. The fresh IBB stream is combined in line 6 with the IBB recycle stream from line 5 and flows from makeup source through line 6. By means of a valve device (not shown), the combined IBB stream is pressurized by the pump 7 and enters the middle part of the extraction reactor 3 through the line 8 and the liquid distributor 9 having a plurality of openings. Alternatively, if there is another finishing reactor (not shown), the combined IBB stream passes through the liquid distributor 11 with multiple openings, through line 10 and from the bottom of the extraction reactor 3. You may enter. In another case of the preferred embodiment shown in FIG. 1, the IBB feed stream forms a discontinuous, light IBB-enriched phase and moves upwards through the dense HF-enriched phase of the continuous phase. IBB reacts with the acetylating agent to remove IBAP, HF, H ₂ O, and / or acetic acid byproducts, which are absorbed in the dense, HF-rich phase of the continuous phase, as described above. To generate. Such a dense phase containing IBAP, HF, and most often some acetic acid and AcF is withdrawn as a reaction product through line 12. Unreacted I
Some of the lighter IBB-rich phases of the discontinuous phase containing BB are
Collected at the top of the extraction reactor 3 and recycled through line 5 as described above.

In addition to the reaction producing IBAP with the acetylating agent in the dense HF-rich phase of the continuous phase, some IBB in the discontinuous light IBB-rich phase remained unreacted and dissolved IBB Are contained in the dense HF-rich phase on the order of about 1% to 10%. When the IBB feed stream enters the extraction reactor 3 through line 8 and liquid distributor 9, the HF-enriched phase containing the acetylating agent and some dissolved IBB flows from the liquid distributor 9 to the reaction product. Moves downwards to the bottom of the extraction reactor 3 which is withdrawn via line 12. This causes the dissolved IB
A residence time is obtained for B to further react with the acetylating agent in the homogeneous system and further IBAP is formed. In this operation, the lower part of the extraction reactor 3 shown as number 13 in FIG. 1 corresponds to the finishing zone. As mentioned above, the same reaction may take place in the finishing reactor, which is a completely separate vessel from the extraction reactor.

In FIG. 1, P1, P2, P3, and P4 represent sampling points that are periodically removed and analyzed.

Referring now to FIG. 2, the operation of the extraction reactor 3 is carried out in the same way as described in the description of FIG. 1, the feed stream of IBB is directed to the middle or bottom of the extraction reactor 3 and the liquid The acetylating agent dissolved in HF enters the extraction reactor 3 through line 1 as a mixture of acetyl fluoride and acetic acid, which is almost always HF recovery column 20 and possibly light end column 30. Obtained as a recirculation stream from. The mixture of HF and acetylating agent in the light end column 1 has a HOAc: AcF molar ratio in the range of about 0: 1 to about 2: 1, and a more preferred range is about 0.25: 1 to about 2: 1. The most preferred range is HOAc: AcF from about 0.65: 1 to about 1.
The range is 3: 1. The HF content of the mixture can be varied if desired. Typically (H for HF
The molar ratio of OAc + AcF) is about 1: 5 to about 1:25.
The preferred range is from about 1:10 to about 1: 2.
The range is 0.

The reaction product from the bottom of the extraction reactor 3 contains IBAP, HF, and HOAc, with all or most of the IBAP complexed with HF, line 1
It is transferred as a feed through 2 to the top of the HF removal column. Acetic anhydride is in column 20 in two lines, line 2 slightly below the feed point of the feed stream from line 12.
1 and / or supplied through line 22 below the column and is disclosed in US Pat. An amount sufficient to react with substantially all HF complexed with IBAP or acetic acid as disclosed in 4,990,681 is provided. The products of this reaction are AcF and additional HOAc. Supplied and free HF, AcF, and HOAc
Like the unreacted IBB, it is withdrawn from column 20 as overhead through line 23 and, after passing through condenser 24, is recycled to extraction reactor 3 through lines 25 and 1. According to another method, the column can be operated such that the overload stream through line 23 contains only HF and AcF and all HOAc is withdrawn as part of the bottom stream containing HOAc and IBAP. Such bottoms stream is withdrawn through line 26 and flows to light end column 30 where it is separated into a IBAP enriched bottoms stream withdrawn from line 31 and a HOAc enriched overhead stream withdrawn through line 32. . The bottom stream 31 containing IBAP is sent to a heavy end column (not shown) to remove less volatile impurities than IBAP and IBAP can be further purified by other purification means before being utilized. . HOAc from column 30
The overhead stream 32 containing is condensed by condenser 33 and is recycled to the extraction reactor 3 as stream 35 with condensed overhead stream 25 from the HF removal column 20 as feed through line 1 as described above. be able to. The remainder of the stream containing HOAc from light end column 30 is removed from the system through light end column 34.

The present invention will be described in more detail based on the following examples.

Example 1 In two parts of the extraction reactor 3 shown in FIG. 1, a 20 foot 8 "pipe is 5/8" pall ring.
rings)). The reactor is maintained at 58 ° C and is at a pressure sufficient to bring the solvent to a boil, ie about 4
It was kept at 0 to 60 psig. An HF solution containing 19 wt% AcF and 15.2 wt% HOAc at 185 lb / hr was supplied to the top of the reactor through line 1.
This is obtained as a recycle stream from the HF removal column 20 and the light ends column 30 as shown in Figure 2, which forms a dense HF enriched phase of the continuous phase. Figure 1
As shown in Figure 3, the IBB feed stream is fed through line 10 at a rate of 74 lb / hr to the bottom of the reactor along with the flow to the middle of the blocked reactor. The light, IBB-rich phase of the discontinuous phase is formed in the bottom part of the reactor and migrates to the top of the vessel with low density and almost no dissolution in the HF-rich phase of the continuous phase.
A reaction takes place between AcF and some of the HOAc as the acetylating agent, and IBB, producing IBAP, which is extracted into the continuous HF-rich phase, which also produces HF as a byproduct and optionally water. To do. The IBB-enriched phase containing unreacted IBB is collected at the top of the vessel and, after phase separation, through line 5, optionally line 10,
It is recycled to the bottom of the vessel at 58.8 lb / hr as the BB feed (including both recycled IBB and makeup IBB). Fresh IBB was added continuously through lines 6 and 10 at a rate of 15.2 lb / hr to dissolve in the HF-rich phase and to make up for the portion consumed in the reaction. 3200 lb / hr of HF-rich phase was recovered from the bottom of the extraction reactor, the HF-rich phase being the HF in the feed stream and the H produced as a by-product of the acetylation reaction.
F plus the desired product, IBAP, and unreacted IB
B, AcF, HOAc and other by-products. P4
A sample of the HF-enriched stream withdrawn from was treated with ice water to remove HF, neutralized, and extracted with an organic solvent. After removing the solvent, the remaining organic portion was 55.1 wt% IBAP and 37.5 wt%
Of IBB. The analysis result of the sample of the IBB feed stream taken out from P3 was 0.3 wt% of IBA.
P, 57.6 wt% IBB, and 1.8 wt% H
It showed the presence of fluorides derived from F and AcF.

The HF-enriched product stream from the extraction reactor 3 is led through line 12 to an HF removal column 20 containing a theoretical plate number of trays 30, Ac ₂ O and HF and HOAc complexed with IBAP. Reacts to produce AcF, mainly H
The light components of F and AcF are the same as those described in the first mentioned US Pat. As described in US Pat. No. 4,990,681, there is stripped overhead for recycling through line 1 to the extraction reactor 3. The HF-enriched feed stream is fed to the tray 26, 28, or 30 of the column 30 near the top of the tray. Ac ₂ O is 14 lb / h
It is fed to the column 20 at r below the feed point of the HF-enriched feed stream, the majority of Ac ₂ O is fed to trays 20 or 24, and a small amount is fed to trays 6, 9 or 14.
A 49 lb / hr product stream was transferred from the base of column 20 through line 26, which contained 26.9 wt% IBAP, 5.9 wt% IBB, 61.6 wt% H.
It contained OAc, 2.1 wt% Ac ₂ O and other by-products.

The product stream from the HF removal column 20 is
Sent to the light end distillation column 30 through the in 26
And the bulk of HOAc is IB as an overhead stream.
Removed from AP product under conditions of 10-50 mmHg
And further refined. Overhead flow is an extraction reaction
It is suitable for recirculation to vessel 3 and is available via line 32.
Emitted and condensed in line 33, 88.1 wt% HO
Ac, 3.5 wt% Ac ₂O, and 5.9 wt%
It contained IBB. Product flow of about 14.4 lb / hr
This is transferred via line 31, which is 91.6 wt
% IBAP and residual by-product bar with higher boiling point
Included Luk. The latter is a heavy-end distillation column.
Further purified and substantially removed.

Example 2 The apparatus configuration is the same as in Example 1, but the IBB is fed to the middle of the extraction reactor rather than to the bottom, so that the bottom part of the vessel acts as the finishing zone and the continuous phase HF The enriched phase was given additional residence time, and the acetylating agent, in most cases AcF, dissolved in the homogeneous phase I
The reaction with BB proceeds further, and the yield of IBAP improves. The reactor temperature was kept at 60 ° C. The feed, fed at 290 lb / hr to the top of the reactor via line 1, was 6.8 wt% AcF and 10.3 wt% HOA.
c was included. IBB via line 8 89 lb /
It was fed into the middle of the reactor at a rate of hr. 16.4l
IBB of b / hr was continuously added via line 6, consumed in the reaction and replenished with dissolved in the HF-rich phase, via line 12 from the bottom of the reactor 307 l.
The b / hr HF solution was removed. Analysis of the organic portion of this stream similar to Example 1 showed 78.8 wt% IBAP, 13.3 wt% IBB and the sample from P2 in the middle of the extraction reactor 3 was 66.4 wt. % IBAP and 27.7 wt% IBB.

The stream withdrawn from the extraction reactor 3 via line 12 was fed separately to 13 lb / hr Ac ₂ O to the 30 trays of the HF removal column 20, as shown in Example 1. It was The solution was continuously withdrawn from the bottom of the column, 34.0 wt% IBAP, 0.3 wt
% IBB, 59.9 wt% HOAc, 3.0 wt%
Of AcO, and other by-products.

Separation of HOAc from the crude acetylated product of HF removal column 20 is accomplished in the same manner as in Example 1 by distillation on light end column 30 at 10-50 mm Hg. The overhead from the distillation column is 94.8 wt% HOAc, 4.6 wt% Ac ₂
O and 0.5 wt% IBB. The product stream contained 92.2 wt% IBAP and was continuously withdrawn from the base of the column.

Examples 3-24 In these examples, the procedures and equipment for operating the extraction reactor 3 were similar to those of Examples 1 and 2, except for certain conditions such as feed stream velocity and temperature. Is the same. In Table 1 the rate of product withdrawn via line 12 (product rate), I via lines 8 and 10
BB feed rate (IBB feed rate), HF and acetylating agent feed rate via line 1 (HF feed rate), IBB make-up rate via line 6 (IBB make-up), operating mode (mode ), Mode 1 is a mode in which IBB is supplied to the middle portion of the extraction reactor 3 via the line 8 as in Example 2, and mode 2 is the extraction reactor 3 via line 10 as in Example 1. Shows the mode supplied to the bottom of, and shows the operating temperature (temperature).

[0041]

[Table 1]

P1, P2, P3 and P shown in FIG.
The analytical results of the various flow samples taken from 4 are shown in Table II.

[0043]

[Table 2]

The experiment, the results of which are shown in Table II, was carried out in mode 1 and the IBB was dissolved in homogeneous phase in the finishing zone.
Further acetylation is allowed to take place between the acetylating agent and the acetylating agent so that the product stream withdrawn from the bottom of the extraction reactor is always in the middle of the extraction reactor, in the finishing zone below the IBB feed point. I higher than the mixture
Has a content of BAP. This result shows the importance of further acetylation in the finishing zone of dissolved IBB. Further, comparing the results of the experiments with Mode 1 with those of Mode 2 where the finishing zone is not used, the product stream withdrawn from the bottom of the extraction reactor in Mode 1 often leads to a mode 2 The ratio is higher than the ratio of IBAP when it is operated in. Therefore, the use of finishing zones or reactors is often useful for high yields of IBAP.

In Examples 21 and 22, the amount of feed containing aromatics fed via line 10 in FIG. It is the same or almost the same as the thing. Recycle of aromatics from line 5 from the top of the extraction reactor is not very high. this is,
This occurs when the aromatics have reacted sufficiently and there is only a small amount of aromatics left at the top outlet of the extraction reactor. According to the data of Example 21, line 6 provides more makeup make-up aromatics-containing feed than the sum of recycled aromatics and make-up feed, which is physically present. It is impossible.
This is an error in the feed rate or flow measurement of recycle from line 5 to the top of the extraction reactor.

It is preferred to react with essentially all the aromatic compounds by passing once through the extraction reactor,
Because the experimental data is an unfavorable isomer,
This is because the isomer of the desired acylated or alkylated product is shown to increase (become more likely to be formed) when the unreacted aromatic compound is recycled.

Example 25 An autoclave with a window for observing the HF solution was charged with 61.2 g acetic anhydride and 60 g.
g HF was charged. The mixture is warmed to about 80 ° C,
1,1,3,4,4,6-hexamethyltetralin (H
MT) was fed to the bottom of the autoclave. A second phase was observed to form on top of the autoclave.
After about 10 minutes, samples of the upper and lower phases of the autoclave were taken. The upper phase is unreacted H
MT (about 33 wt%) and acylation products 1,
It contained 1,3,4,4,6-hexamethyl-7-acetyltetralin (HMAT) (about 2 wt%), and residuals of HF and acetic anhydride. The lower phase is about 2 wt% HM
T, about 2.5 wt% HMAT, with residuals of HF and acetyl species. This autoclave experiment does not show the separation of the reaction products obtained in the preceding examples, but serves to predict the phase behavior in the reactor described in the preceding examples.

Example 26 This example demonstrates the limited solubility of p-cymene in HF and that p-cymene (methylisopropylbenzene) can be acylated or alkylated by the method of the present invention.

26.8 g of p-cymene and 150 g of HF were added to the autoclave at about 0 ° C. The autoclave contents were stirred for about 5 minutes. The stirring was stopped and the phases were separated in the autoclave for about 30 minutes. The sample taken from the top of the autoclave contained about 93 wt% p-cymene and about 4 wt% HF. A sample taken from the bottom of the autoclave was about 1% p-cymene and about 9%.
It contained 9% HF.

Example 27 Alkylation reactions using HF as catalyst / solvent are possible with the process of the present invention.

Mixture of 33.6 g of 3,3-dimethyl-1-butene and 13.4 g of p-cymene, 100 g of HF
Was reacted in an autoclave with stirring at about -40 ° C for about 1 hour. The product mixture was transferred to ice / water, neutralized with KOH and extracted with ethyl acetate. The ethyl acetate extractant was removed on a rotary evaporator to remove the alkylated product 1,1,
36 g of an organic substance containing 19% by weight of 3,4,4,6-hexamethyltetralin (HMT) was obtained.

The alkylating agent used in the process of the present invention is an unsaturated C ₂ -C ₂₀ alkyl, preferably an unsaturated C _2-.
It is C ₁₀ alkyl.

In the present invention, the aromatic compound forms a continuous phase,
Also included are embodiments in which the HF-rich phase creates a discontinuous phase. Typically, the HF-rich phase moves down the aromatic-containing phase, collects at the bottom of the extraction reactor, and is treated in a manner similar to the preferred embodiment described above.

The present invention further includes an embodiment in which the multi-step reaction uses a laminar flow of an aromatic compound-containing phase and an HF-containing phase. A laminar flow is for example in a tube reactor in which the aromatic reactants, acetylating agent and HF are collected at one end of the tube reactor and the reaction proceeds as a mixture under plug flow conditions along the length of the tube. Enable use. The product mixture present in the tube reactor contains unreacted aromatics, hydrogen fluoride, product dissolved in hydrogen fluoride, and unreacted acylating or alkylating agent. The product mixture is then sent to a separation unit, US Pat. Various components are separated by various separation methods disclosed in 4,990,681.

The amount of aromatics fed to the tube reactor and / or the number of stages contained in the reactor is such that the amount of unreacted aromatics remaining in the product mixture present in the tube reactor is small. Adjusted to.

The above embodiments do not limit the scope of the present invention in any way, and those skilled in the art can make changes to the present invention by making obvious modifications and replacing them with equivalents.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a process for alkylation of aromatic compounds in hydrogen fluoride, including an extraction reactor and an optional finishing zone.

FIG. 2 is a schematic diagram of a process for alkylation of aromatic compounds in hydrogen fluoride with an extraction reactor with optional finishing zone, an HF removal column, and a light ends column.

Front Page Continuation (72) Inventor Thomas A. Curtis 29715 South Carolina, United States, Woodholm Cote, Tega Kay 12003 (72) Inventor Timothy Earl Ryan Corp., Texas 78413, United States Corpus. Christie, Burnham Drive 5406, number 823 (72) Inventor Edward M de la Garza Texas 78412, USA Corpus Christi, Montclair 218 (72) Inventor Charles B Hilton, Rhode Island, USA 02852, Laurel Ridge Lane, North Kingstown 284 (72) Inventor Thomas M. Kenneson Texas 78408, Corpus Christi, Mars 9349 (56) Reference JP-A-60-197631 (JP, 197631) A) JP-A-60-92226 (JP, A) JP-A-60-61540 JP, A) (58) investigated the field (Int.Cl. ^7, DB name) C07C 2/70 C07C 15/24 C07C 45/46 C07C 49/76

Claims (9)

(57) [Claims] 1. A continuous process for the alkylation of aromatic compounds in hydrogen fluoride comprising the steps of: a) feeding hydrogen fluoride and at least one alkylating agent to an extraction reactor; Forming a hydrogen fluoride-rich phase, b) feeding a material containing an aromatic compound to the extraction reactor to form a second aromatic compound-rich phase, and c) the first fluorine-containing phase. Contacting a hydrogen hydride enriched phase with some of the second aromatic compound enriched phase in the extraction reactor,
Reacting the alkylating agent with the aromatic compound to form an alkylated product of the aromatic compound and extracting into a hydrogen fluoride phase. 2. At least a portion of the aromatic compound remains unreacted after step c) and the unreacted aromatic compound is recycled to the outside, whereby the unreacted aromatic compound. is used in combination with the new aromatic compounds, the reaction is continued by the extraction reactor, according to claim 1, wherein
Way of . 3. A process according to claim 1, wherein essentially all the aromatic compounds of the second phase are reacted after step c). 4. The aromatic compound is isobutylbenzene, methylisopropylbenzene, chlorobenzene, diphenyl, diphenylmethane, triphenylmethane, naphthalene, 2-methylnaphthalene, tetralin, 1,
The method according to claim 1 or 2, which is selected from the group consisting of 1,3,4,4,6-hexamethyltetralin, and pantrene. 5. The aromatic compound is 1,1,3,4,
The method according to claim 4, which is selected from the group consisting of 4,6-hexamethyltetralin and methylisopropylbenzene. 6. The unsaturated C ₂ -C ₂₀ alkylating agent
The method according to claim 1, 2 or 3, which is alkyl. 7. The C ₂ -C ₁₀ unsaturated alkylating agent.
The method according to claim 1, 2 or 3, which is alkyl. 8. The process according to claim 1, wherein the hydrogen fluoride-rich phase is the continuous phase of the reaction medium of the extraction reactor. 9. The aromatic compound-enriched phase is a continuous phase of a reaction medium of an extraction reactor.
The method described in the section.